Thread-rolling device.



A. N. BAILEY.

THREAD ROLLING DEVICE. I MPPL'ICATION FILED NOV. 2h l9l3- s swans-saint I.

Pmmm 6; 19115.

A. N. BAILEY. THREAD ROLLING DEVICE. APPucnnou FILED NOV. 21. 1913.

Patented July 6 5 SHEETS-SHEET2.

' Al N: THREAD ROLLING DEVICE. APPLICATION FILED NQV. 21' I913- 5 SHEETS-SHEET 3- Patented July 6, 1915.

A. N. BAILEY. 7 THREAD ROLLING DEVICE.

APPLICATION FILED NOV. 2|, I913.

- Patented My 6, 1915.

5 SHEETS-SHEET I.

A. N. BAILEY.

THREAD ROLLING DEVICE.

APPLICATION FILED NOV. 2|. 191s.

Patented July 6,, 1915.

5 SHEETS-SHEET 5.

ammo/4 S formation of all a manner.

ARCHER N; BAILEY, 01F TOBBINGTON, CONNECTICUT, ASSIG'rNO 1'0 STAND t 1" l COMPANY, OETORRINGTON, CONNECTICUT, A GORPOTION 0E MAINE.

THEE-ROLLING- ]DEVIGE.

Specification of Letters Patent.

Patented July e, min.

I Application filed November 21, 1913. Serial Ito. 802,281.

To all whom. it may concern Be it known that I, ARCHER N. BArLEY, a citizen of the United States, residing at Torrington, in the county of Litchfield, State of Connecticut, have invented certain new and useful Improvements in Thread- .Rolling Devices, of which the following is a description, reference being had to the accompanying drawing and to the figures of reference marked thereon.

My invention relates to improvements in devices for rolling threads on bolts, screws and the like, and more particularly to the rolling of threads by doublerolls.

The principal object of my invention is to provide an attachment for an automatic screw machine, or the like, designed to produce a screw thread upon portions of the product of such a machine which cannot, because of its location, be operated upon by the ordinary cut threading dies nor roll threaded with a suflicient degree of accuracy with onlyone roll.

A further object is to provide double roll threading devices which are only rotated by being brought into contact with the revolving blank to be operated upon; in which the threads is started at the same time and the rolls turn several revolutions to complete the operation; the entire periphery of the rolls being threaded.

A further object is to provide an attachment which can operate while the tool slide is being drawn backward, in which condition no work is usually being done.

Another object is to provide double roll threading devices which are designed to operate upon a blank of the approximate pitch diameter of a finished screw or bolt and by which the metal displacedto form the bottom of the groove is forced outward thus forming the outside or top of the thread without increasing the length of the blank.

My invention, therefore, consists in the various arrangements and construction of parts for accomplishing the above named objects and in the various matters hereinto in the apably connected with threading attachment applied thereto. Fig. 2' is an enlarged side elevation of my roll threading attachment and the mechanism for bringing it into and out of engagement with the blank; the attachment being shown as removed from the machine. Fig. 3 is an end elevation of the attachment. Fig. 4: is a longitudinal section on line d4 of Fig. 2. Fig. 5 is a similar view on line 5-5 of Fig. 2. Fig. 6 is a vertical section on line 6-6 of Fig. 2. Fig. 7 is an enlarged bottom plan view of the holder and threading rolls. Fig. 8 is a horizontal sectional view through the holder and threading rolls. Fig. 9 is a detail showing the manner in which the threading rolls operate upon a blank of approximately the pitch desired and showing also the finished product. Fig. 10 is an enlarged transverse view through the spindle head of an automatic screw machine showing the manner in which the roll threaders are brought into contact with a revolving blank. Fig. 11 is an enlarged side elevation of a modified form of threading roll holder. Fig. 12 is an end elevation thereof, and Fig. 13 is a side elevation illustrating a modified form of operating mechanism for the threading rolls.

The present invention is primarily designed for use on an automatic screw machine and is constructed to automatically operate at a predetermined period upon a properly dressed blank.

In screw machines of the multiple spindle type the product is cut and dressed to the required shape and size by certain of the tools properly positioned upon the machine, the blank being revolved while being operated upon by these tools. In addition tothe work revolving with the spindles in presenting it to the tools, the head or tool carrier in which the spindles are positioned is also rotated at certain predetermined intervals, thereby continuously dressing the product until ready for the screw threading operation and it is to a machine of this character that my attachment is especially adapted.

The machine herein shown is of the well known type above mentioned and the frame 1 supports the various operating mechanisms. The driving mechanism 2 is suitthe moving parts above the-bed 3 of the machine and operatesto move the head or carrier 4 which carries the usual dressing tools. It is to this tool carconstruction.

in to give a slight pivotal action to allow The several mechanisms and parts are operated through the power transmission 9, (belt or motor driven) and these parts and mechanisms which are not features of the invention it will be understood are of usual construction and need not he referred to herein except generally.

Figs. 2 and 6 illustrate most clearly the roll threading device and its operating mechanisms in which figures it is shown detached from the machine. The bar or casting 10 is shown as having a dovetail groove 13 and fastened to a corresponding dovetail on the projection 14: bolted to the spindle head 5 of the machine. Another bar or casting 11 is slidablymounted on the bar or casting 10,

by the dovetail 15 and gib 16 and is formed with a cut out portion 17 in which fits the stem or shank 18 of the head or casing 12 on which the threading rolls or dies and their connecting gearing are held; the stem or shank 18 is held securely in place by the clamping bar 19 and cap screw 20, as shown in Fig. 5 and an adjusting screw 21 is provided above the stem to regulate the position of the holder or casing carrying the threading rolls.

The casing or head 12 in which the threading rolls are mounted is preferably.

constructed of two parts 22 (the main housing) and 23 (the covering plate). This casing is pivotally connected to the stem 18 as at 24 by the bolt, and the lower end of the stem extends into the recess 25 in the main housing 22 fitting just loosely enough thereof an easy contact of the rolls with the blank and ready Withdrawal therefrom, as will be understood.

Mounted within the casing 12 are the threading rolls or dies 28 and 29 which are preferably made of the best hardened'ma- 'terial and are formed with the standard size threads with which the finished product is to be provided. They may be of any desired width according to the length of the screw thread desired upon'the product. They are mounted on shafts or spindles 30 and 31 and spaced therefrom by bushings 32 and 33. Gears 34-and 35 are respectively secured to the threading rolls or dies and mesh with an intermediate gear 36. By this train of gears a steady and ,uniform rotation is given .each roll or die while operating upon the blank.

Referring now to Figs. 7 and 8 the gears 3-1 and 35 are herein shown as fastened to the threading rolls or dies by screws 37 for effecting the rotation of each roll with its gear, but other suitable fastening means may be employed. In order to effect a free rotation of the threading rolls within the casing and at the same time guard them against any side thrust which would tend to produce an uneven thread, small pins 38 and springs 39 as shown in Fig. 8 are provided upon opposite sides respectively of the rolls, and by reason of their contact with the housing and covering plates prevent this side thrust.

In forming screw threads upon a blank the threading dies are designed to operate upon a blank of approximately the pitch diameter of a finished. screw and the metal transferred from the bottom of the groove of screw thread is forced outwardly, thus forming the outside or top of the thread, as shown in Fig. 9. To illustrate, assuming an example of standard screw x 13 U. S. S. with a diameter to start with of of .450". This represents the blank or pitch diameter. When the threads have been rolled therein the diameter at the root of the .thread is .400 and at the top of the thread .500"; thus the metal is simply transferred in the rolling process. In this operation, the threading rolls uponlbeing withdrawn stop revolving, thereby preventing any mutilation of the threads as the work is moved farther.

In Figs. 11 and 12 is shown a modified form of this part of my invention in which the train of gearing is positioned at the opposite side of the casing. This train consists of small gears 3-1 and 35' meshing with a train of small gears 36. In reducing the size of the gears the blank may be inserted from the opposite side should there be a part. of the blank which would interfere with the, larger gear 36. Thus it will be seen that when the work or blank is inserted fromthe front, three gears are used and when from the back one gear is used; this construction may, however, be varied according to the size of the work and the way in which it is presented to the threading rolls.

The operating mechanism for raising and lowering the threading dies upon the blank is best shown in Figs. 2, 3, 4 and 6. It consists of a bar 40 suitably fastened to the tool carrier 4 of the screw machine, or any other properly timed and moving part. Formed in this bar is a cam groove 41 in which operates a roller 42 carried by the movable holder 11. The bar operates through an opening provided in the member bar or casting 10, which opening is covered by the plate 43. The roller 42 is carried on a: stud 44 which is secured to the member 11 by the screw 45. roller travels in the cam groove 41 in bringing 'thedies into and out of engagement with the blank as follows: Assuming the bar which is secured to the tool carrying slide to be moving in the direction of the arrow shown in Fig. 2, the

- roller will take a position in the cam groove as indicated at a. A further movement of the bar inthe same direction will cause the roller to dropto. the position in the groove marked 6. As this dropping movement of I the roller takes place, the holder or memher 11 is lowered to a position just above the blank to be threaded. The bar being then moved in the reverse direction, the

' roller will descend in the groove to the position indicated at 0. In this lowermost position of the roller, the threading dies have been 'lowered'in'to contact with the blank,

the necessary thread forming depth. During the continuing movement of the bar in this reverse direction from c to the position marked d the actual threading operation takes place. The moment the threading dies be employed. In this construction the threading dies operate conversely to the other design. A movement of the bar in thedirection of the arrow in this instance, will, assuming the roller to be in the position indicated at a, move in the cam groove 41, depressing the latch 46', arriving at the position b. A reverse movement of the bar will cause the roller to move down the incline'e on to the blank. From the position 0 to d the threading takes place, when the roller continues up to the position f in the cam groove and the same operations repeated. By this last construction, the blank is threaded during the forward movement of the bar, as contradistinguished from the first described construction, wherein the roll threading takes place during the reverse or tt is also shown operating upon a blank backward movement of the bar. For work which does not require much time on the other dressing operations, the modified form is'preferable. r

While I have illustrated the use of a roller 42, it will be understood that such roller need not necessarily be used on the end of the stud 44.

In Fig. 10 of the dra spindles 6 are shown in the spindle hea 5, The relative position of the roll three '1 "1g springthe multi 1e] In this position the roller is operatingin the lowermost part of the camgroove 41. lhe line of descent of the threading dies is pref erably at right angles to the axis of the blank and all of the threads'are started at the same time and completed all together. Upon the withdrawal of the threading dies from the blank the inner part of the head on which the spindles are mounted is rotated in the direction of the arrow, thereby bringing the next blank into position for the threading operation.

It will be apparent, that while I have shown my double roll threader as applied to a screw machine of the multiple spindle type, it is not so limited, and may be used in conjunctionwith other mechanisms and machines capable of presenting a revolving blank for threading. I

From the foregoing, it will be obvious that an accurate and eficient roll threader is providedv capable of forming a screwthread upon a revolving blank in a minimum space of time, by simultaneously contacting therewith and simultaneously withdrawing therefrom.

Having thus described my invention, What I claim is:

-. 1. A thread rolling device for a revolving blank including in combination a rotating spindle adapted to revolve theblank, double thread rolling dies or rolls arranged above 'said rotating spindle in a fixed predetermined position with relation to each other and means for lowering the rolls into engagement with the blank whereby said rolls are operated by the rotation of said blank.

2. A thread rolling device for a revolving blank including in combination a rotating spindle. adapted to revolve the blank, double threadvrolling dies or rollers arranged above said rotating spindle in a fixed predetermined position with relation to each other and means including a roller and cam for lowering the rolls into engagement with the blank whereby said rolls are .operated by the rotation of said blank.

3. A thread rolling device for a revolving blank including in combination a plurality of rotating spindles adapted to receive and revolve the blanks, thread rolling dies or'rolls arranged above the said spindles in a fixed predetermined position with relation to'each other, and adapted to successively engage the blanks and means for lowering the said rolls into engagement with the revolvin -.blanks whereby said rolls are operated y the rotation of sand blanks 4. threadrolling device for a revolving blank, comprising double thread rolling dies or rolls arran ed to move in parallel relation with one other, means for mdving the rollsinto' engament with the not blank, whereby the former are operated by the rotation of such blank, and gearing between the rolls for operating the same in unison upon opposite sides of the blank.

'upon a blank, comprising a suitable casing, means for moving the casing toward and out from the blank, thread rolling dies or rolls supported in said casing, and provided with continuous cutting surfaces adapted to be rotated by the rotation of the blank. gearing between the dies oi; rolls, and

means for preventing side thrust of the rolls, comprising pins and springs upon opposite sides thereof supported between the walls of the casing.

7. In combination with a movable carriage supporting a blank, and provided with a cam groove having a spring pivoted latch automatically operating in the groove, thread forming. rolls or dies supported on a movable franie on said blank carriage and provided witha member engaging said cam groove whereby, in the movement of the blank or tool carriage back and forth, the thread rolling dies are automatically brought into and out of operative relation with the blank to be operated upon.

In testimony whereof, I affix my signature, in the presence of two witnesses.

ARCHER N. BAILEY. Witnesses:

CHARLES L. STURTEVANT,

. CBanLEs M. HIBBARD. 

